A groundbreaking study presented at the December 2025 San Antonio Breast Cancer Symposium challenges longstanding concerns about menopausal hormone therapy (MHT) in women with BRCA mutations. The matched prospective analysis of 1,352 menopausal women (676 matched pairs) with BRCA1 or BRCA2 mutations found that MHT use was inversely associated with breast cancer risk over a mean 5.6-year follow-up. Notably, estrogen-only MHT demonstrated a 63% reduction in breast cancer risk compared to non-users, while conjugated estrogen plus bazedoxifene showed zero cancer cases among 43 users.

The findings are particularly significant for women undergoing preventive bilateral salpingo-oophorectomy at young ages (average 43.8 years), who face severe menopausal symptoms alongside elevated baseline cancer risk. Lead researcher Dr. Joanne Kotsopoulos emphasized the need for personalized, evidence-based menopause management in this high-risk population, noting that MHT appears safe when not otherwise contraindicated and can address both acute and long-term consequences of surgical menopause.

Citation: Kotsopoulos J. Menopausal Hormone Therapy and Breast Cancer Risk in Women with BRCA Mutations. Presented at: San Antonio Breast Cancer Symposium; December 9-12, 2025; San Antonio, TX.